stall will not restart after around three hours of continuous driving

[Dagwood30]

I deliver mail out of a 01 exp sport, the problem I'm having is after around three hours of continuous driving the engine will start to hesitate and stumble if you will,the problem gets progresively worse as I keep driving until it will stop running altogether. After around an hour or so it will start right back up and run fine. I have pulled the obd codes and it says rich pe lean condition caused by bad maf sensor or fuel pressure issue. The problem occurs usualy on very hot days,it is an intermitent problem that does not happen every day, I am stumped! Don't want to pay 130 for a maf sensor and still have the same problem,clogged cat converter possibly? Any advice would be apreciated,I'm no mechanic but am capable of minor repairs ,maybe someone has experienced the same problem perhaps.:exporange

 

[duke16]

You can get a fuel pressure gauge to verify the fuel pressure. You could also replace the fuel filter, there pretty cheap.

As for the MAF, try getting some MAF cleaner from Autozone/Advance and give it a spray.

 

[2000StreetRod]

Probably not the MAF sensor

I doubt that a MAF sensor would become faulty after a few hours and then "recover" after an hour.

What are the specific DTCs?

OBD-II compares the throttle position via the TPS to the MAF sensor value for correlation.

Does your Sport start to overheat after a few hours?

 

[Dagwood30]

specific DTC

P0171 Fuel trim bank one condition ,No overheating problems .

 

[budwich]

as mentioned, check your fuel pressure but also try and monitor your vacuum pressure with a gauge.

 

[Dagwood30]

I doubt that a MAF sensor would become faulty after a few hours and then "recover" after an hour.

What are the specific DTCs?

OBD-II compares the throttle position via the TPS to the MAF sensor value for correlation.

Does your Sport start to overheat after a few hours?

P0171 Fuel trim bank one condition, no overheating problems.

 

[410Fortune]

sounds to me like your fuel pump is getting weak, BUT you should first check the fuse and relay


when the fuel pumps get old they will do this, they will heat up and not want to supply adequate pressure any more...soon it will just quit then you will KNOW the problem

I second the check fuel pressure, after you listen for the pump to prime

 

[Dagwood30]

sounds to me like your fuel pump is getting weak, BUT you should first check the fuse and relay


when the fuel pumps get old they will do this, they will heat up and not want to supply adequate pressure any more...soon it will just quit then you will KNOW the problem

I second the check fuel pressure, after you listen for the pump to prime

What would be an adequate fuel pressure reading,is the valve located on one of the fuel injector rails? Does this require a specific gauge? May sound strange but this has been an intermitent problem for around 2 years,I know talk about procrastination ,don't you think the fuel pump would have failed by now,it has 150,000 miles on it and gets beat on all day long delivering mail,this has been the only signifigant problem I've had out of the vehicle in 5 years,guess I can't complain ,it has been a dependable vehicle overall. Thanks for the tips very usefull info for someone who depends on his vehicle everyday,it is how I make my living.Thanks again

 

[2000StreetRod]

Only 1 bank?

P0171 is bank 1 too lean. I'm surprised that if the problem is bad enough for the engine to stop that both banks don't register as too lean (P0174 for bank 2). Does the engine die before or after the CEL? It may be that it dies before the second bank can be recorded. If it is the fuel pump pressure, both banks should be affected. Have you ever replaced your inline fuel filter? Ford recommends replacing it every 30,000 miles. It could be partially clogged causing your fuel pump to overheat and shut down. I suspect clogged fuel filters is the main cause of fuel pump failure. See http://www.explorerforum.com/forums/showthread.php?t=256425 for fuel pressures. These tests may all pass with a partially clogged filter.

Here's another idea. Your fuel tank could be developing a partial vacuum after driving for several hours. Try removing the filler tube cap and depressing the check valve in the filler tube to vent the tank every hour or so of driving. If that solves your problem then you have an Evaporative Emissions Control System malfunction or a very weak fuel pump.

 

[Dagwood30]

P0171 is bank 1 too lean. I'm surprised that if the problem is bad enough for the engine to stop that both banks don't register as too lean (P0174 for bank 2). Does the engine die before or after the CEL? It may be that it dies before the second bank can be recorded. If it is the fuel pump pressure, both banks should be affected. Have you ever replaced your inline fuel filter? Ford recommends replacing it every 30,000 miles. It could be partially clogged causing your fuel pump to overheat and shut down. I suspect clogged fuel filters is the main cause of fuel pump failure. See http://www.explorerforum.com/forums/showthread.php?t=256425 for fuel pressures. These tests may all pass with a partially clogged filter.

Here's another idea. Your fuel tank could be developing a partial vacuum after driving for several hours. Try removing the filler tube cap and depressing the check valve in the filler tube to vent the tank every hour or so of driving. If that solves your problem then you have an Evaporative Emissions Control System malfunction or a very weak fuel pump.

Well I Pulled the inline filter and it was full of what looked like mud,is this any indication of what is in my fuel tank,granted the filter has not been changed since I owned the vehicle,could this be my problem,or only a sign of the inevitable fuel pump failure, I am trying to get by w/the easiest fix, but have a feeling that by the look of the filter the fuel pump is the real problem,I will do the pressure test after new filter is instaled,also is there some sort of drain plug for the fuel tank to rid it of the sludge that was in the fuel filter?

 

[2000StreetRod]

Tank drain

Well I Pulled the inline filter and it was full of what looked like mud,is this any indication of what is in my fuel tank,granted the filter has not been changed since I owned the vehicle,could this be my problem,or only a sign of the inevitable fuel pump failure, I am trying to get by w/the easiest fix, but have a feeling that by the look of the filter the fuel pump is the real problem,I will do the pressure test after new filter is instaled,also is there some sort of drain plug for the fuel tank to rid it of the sludge that was in the fuel filter?

My guess is that the restriction from years of accumulation in the filter caused the fuel pump to overheat after a few hours. Submersible pumps incorporate a thermal cutoff to prevent igniting the fuel in the tank. With the restriction removed, it could give you many years of trouble free service. Just because the filter is clogged doesn't mean the tank is full of crud. The only effective way to clean a tank is to remove it and then steam clean it. Afterwards, all of the seals, grommets and the vapor valve assembly would have to be replaced. There is no tank drain. You would have to drive it to nearly empty or siphon out the fuel. Frankly, I wouldn't bother. You'll have a clean filter to catch anything left in the tank that the pump picks up. For next time you may want to change the filter at 20,000 or 25,000 miles instead of the usual 30,000 miles. If the fuel pump passes the pressure tests then it probably has not been permanently damaged.

 

[Dagwood30]

Thank you

My guess is that the restriction from years of accumulation in the filter caused the fuel pump to overheat after a few hours. Submersible pumps incorporate a thermal cutoff to prevent igniting the fuel in the tank. With the restriction removed, it could give you many years of trouble free service. Just because the filter is clogged doesn't mean the tank is full of crud. The only effective way to clean a tank is to remove it and then steam clean it. Afterwards, all of the seals, grommets and the vapor valve assembly would have to be replaced. There is no tank drain. You would have to drive it to nearly empty or siphon out the fuel. Frankly, I wouldn't bother. You'll have a clean filter to catch anything left in the tank that the pump picks up. For next time you may want to change the filter at 20,000 or 25,000 miles instead of the usual 30,000 miles. If the fuel pump passes the pressure tests then it probably has not been permanently damaged.

Thank you for all the info, you may have saved me quite a bit of time and money, I like to do all the work on my sport when I can, don't trust any shops in this area,also glad to have found this site, not only do I love my sport but it makes me money every day as well, with knowledgable people like yourself I think my lil two door will be runnin like it used to in no time,I guess a little preventive maintinence goes a long way,keep you posted

 

[duke16]

What would be an adequate fuel pressure reading,is the valve located on one of the fuel injector rails? Does this require a specific gauge? May sound strange but this has been an intermitent problem for around 2 years,I know talk about procrastination ,don't you think the fuel pump would have failed by now,it has 150,000 miles on it and gets beat on all day long delivering mail,this has been the only signifigant problem I've had out of the vehicle in 5 years,guess I can't complain ,it has been a dependable vehicle overall. Thanks for the tips very usefull info for someone who depends on his vehicle everyday,it is how I make my living.Thanks again

Yup, you should see a valve right on top of the fuel rail.

http://shop.advanceautoparts.com/we...E-TESTER-Actron_9030328-P_N3388_T|GRP2018____

 

[2000StreetRod]

fuel pressures

What would be an adequate fuel pressure reading . . .

At idle with vacuum hose detached from pressure regulator: 40 to 50 psi
At idle with vacuum hose attached: 30 to 40 psi
Maximum pressure: 65 psi
5 minutes after shutting engine off:30 to 65 psi

The fitting on the fuel pressure test port is called a Schrader valve. If you don't have a mating connector, you can remove the valve and attach a hose and clamp.

 

[Dagwood30]

Pressure test pass

My guess is that the restriction from years of accumulation in the filter caused the fuel pump to overheat after a few hours. Submersible pumps incorporate a thermal cutoff to prevent igniting the fuel in the tank. With the restriction removed, it could give you many years of trouble free service. Just because the filter is clogged doesn't mean the tank is full of crud. The only effective way to clean a tank is to remove it and then steam clean it. Afterwards, all of the seals, grommets and the vapor valve assembly would have to be replaced. There is no tank drain. You would have to drive it to nearly empty or siphon out the fuel. Frankly, I wouldn't bother. You'll have a clean filter to catch anything left in the tank that the pump picks up. For next time you may want to change the filter at 20,000 or 25,000 miles instead of the usual 30,000 miles. If the fuel pump passes the pressure tests then it probably has not been permanently damaged.

Ok I did the fuel line pressure test, the readings were normal, 50 Psi at idle, held pressure w/ engine off, I guess my next question is would the pump only give me a insufficient reading while the problem was actually occuring, if the fuel pump is weak or begening to fail wouldn't it give me a low reading anyway? The truck really runs a lot better since the new filter but it did the same thing once last week, could it be a faulty relay, are they affected by excessive heat? The problem seems to only occur on HOT days, I also tried to vent the fuel tank every couple of hours and this had no affect at all, STUMPED!!!!

 

[fallenauthority]

Quick way to test, bring a flathead screwdriver, a can of starter fluid or carb cleaner with you in your truck, next time it dies take the intake tube off the throttlebody open the throttle and do a couple quick hits of carb cleaner into the intake, slip the tube back on and try to start it if it starts it is 100% a fuel delivery issue, which most likely would be fuel pump in this case.

 

[ranger7ltr]

At idle with vacuum hose detached from pressure regulator: 40 to 50 psi
At idle with vacuum hose attached: 30 to 40 psi
Maximum pressure: 65 psi
5 minutes after shutting engine off:30 to 65 psi

The fitting on the fuel pressure test port is called a Schrader valve. If you don't have a mating connector, you can remove the valve and attach a hose and clamp.

Is your truck a 1999 or newer? It should have a returnless fuel system and the fuel pressure regulator is in the tank...And the fuel pressure of the returnless fuel system is 65-72 psi...

I had a similar issue when I first starting driving my truck...It would run fine unless I got on the throttle hard and the engine would start to bog down and die if I didn't back off the throttle quickly to half or less...After changing filters and getting lots of dirty, rusty fuel out of the input AND output side of the filter, I dropped the tank and cleaned it out...

I got plenty of dirt, rust, and sediment out of the tank and treated it with POR-15 to etch then coat the tank...I replaced the pump thanks to the pressure dropping below 60 psi under moderate acceleration....